Add a timer function

[rexkix]

This is the second of three issues. The goal is to make it so I don't need Notepad++ anymore and can use the TFC window instead. They probably are all for the v2 version of TFC.

Issue 2: Add a timer to TFC.

Now my Notepad++ doesn't have this feature, but it's a useful one for bomb defusal. Mostly it'd be useful for Turn The Keys times, but it could also be useful to remind the defuser about announcing Swan resets, amnesia changes, etc.

If a line begins with "### TIMER = " set an alarm for that time. Show the alarm time at the top of the screen as a sticky line.

Extra points if you can do any of the following:

• Allow for more than one timer with format "TIMER = "
• Allow for timers to be reset to their starting time with a RESET button next to the timer. This could be useful for Swan resets / Amnesia changes, etc.